Introduction
Aims of the Paper
The principal aims of this paper are (1) to increase professional health workers’ knowledge of selected research findings and theory so that they may better understand why and under what conditions people take action to prevent, detect and diagnose disease; and (2) to increase awareness among qualified behavioral scientists about the kinds of behavioral research opportunities and needs that exist in public health.
A matter of personal philosophy of the author is that the goal of understanding and predicting behavior should appropriately precede the goal of attempting to persuade people to modify their health practices, even though behavior can sometimes be changed in a planned way without clear understanding of its original causes. Efforts to modify behavior will ultimately be more successful if they grow out of an understanding of causal processes. Accordingly, primary attention will here be given to an effort to understand why people behave as they do. Only then will brief consideration be given to problems of how to persuade people to use health services.
Focus and Limitations of the Paper
Kasl and Cobb recently provided a classification of various behaviors in the health area that provides a useful framework for considering the focus and limitations of the present paper.1 They define health behavior as “any activity undertaken by a person who believes himself to be healthy, for the purpose of preventing disease or detecting disease in an asymptomatic stage.” Illness behavior is defined as “any activity undertaken by a person who feels ill, for the purpose of defining the state of his health and of discovering suitable remedy.” Finally, sick-role behavior “is the activity undertaken by those who consider themselves ill for the purpose of getting well.” In terms of these distinctions, the present paper emphasizes research on the determinants of health behavior and to a lesser extent, research on illness behavior. No attempt will be made to treat the voluminous literature on sick-role behavior for two reasons. First, the public health worker is more centrally concerned with behavior relative to prevention, early detection and diagnosis of illness than he is with behavior in response to diagnosed illness. Second, the author’s research experience is largely confined to studies of health behavior, as defined by Kasl and Cobb.
Another limitation that should be made explicit is that virtually all material to be presented has been drawn from studies of various subgroups of the population of the United States. No attention will be given to the contributions accruing from studies of other cultures.
The Determinants of Individual Health Behavior
Studies of How People Use Health Services
Consideration may first be given to the relationship between studies of how health services are used and an understanding of why health services are used. Do studies of how people use services explain why people use health services? In approaching an answer to this question, a careful distinction should be drawn between studies of utilization whose findings are intended to have immediate application, and studies of utilization which are intended to serve as means to still other research ends. In the first case, information is sought to serve as a basis for formulating and implementing public policy in the health area. Utilization data obtained for such purposes have proved invaluable in the health field.2–4
However, studies of the use of services may also be undertaken as means to achieve the broader aim of increased understanding of why services are used. In this sense, utilization studies are intended to generate hypotheses about why services are used. Such utilization studies have generally failed to accomplish their purpose. Little can be learned from these studies about why people use or fail to use certain services. Evidence in support of this conclusion has been drawn from studies of high and low users of free medical examinations,5 detection tests for cervical cancer,6 polio immunization,7 dental services,8, 9 physicians’ services,3, 10 hospital services11 and from studies of the characteristics of those who do and those who do not delay in seeking diagnosis and treatment of cancer.1, 12
Analyzing the major findings of studies on the patterns of use of preventive and detection services permits certain summary generalizations about the association of personal characteristics with the use of services. In general, such services are used most by younger or middle aged people, by females, by those who are relatively better educated and have higher income (though perhaps not the very highest levels of education and income). Striking differences may nearly always be found in acceptance rates between whites and non-whites, with whites generally showing higher acceptance rates, although occasional exceptions occur.
A review of the previously cited data on utilization of diagnostic and treatment services provided by the physician, the dentist and the hospital, suggests a pattern quite similar to that obtained in connection with preventive and detection services. In general, more females than males visit the physician and the dentist and incur hospitalization, even when hospitalization for pregnancy is excluded. Higher socioeconomic groupings (defined in terms of educational and income level) are also more likely to obtain medical, dental and hospital services, although the associations between income and utilization are becoming less marked.2, 3
With reference to race, whites show much higher utilization rates than non-whites in all three utilization categories (physician visits, dental visits and hospitalization).
The nature of the association between age and utilization of treatment services is generally different from that found between age and seeking preventive and detection services, probably reflecting the effect of objective medical and dental need.
With respect to characteristics of those who delay in seeking diagnosis and treatment of cancer, similar patterns emerge. In general, persons who delay are older, of low educational status and, at least in some studies, males.12
Although most studies of utilization do not throw light on why people use health services, one area of research can be identified in which quite sophisticated efforts have been made to understand health and illness behavior as a function of personal characteristics; an area described by Kasl and Cobb as “variables affecting the perception of symptoms.” Several other workers attempt to link personal and subcultural variables to the individual’s likelihood of perceiving an event as a symptom or to his mode of responding to a symptom. For instance, Koos found a social class gradient in terms of the likelihood of interpreting a particular sign as a symptom.13 Stoeckle, Zola, and Davidson studied the effects of ethnic values upon the specific decision to seek medical attention and on the differential interpretation of objectively similar symptoms.14, 15 Freidson illustrated the different processes through which members of different social groups move in obtaining diagnosis (lay and professional) and in seeking care.16 Suchman attempted an interesting and promising approach which links demographic factors to social structure, both of these to medical orientation and in turn to health and medical care.17
Studies of the kinds performed by Koos, Stoeckle, Zola, Freidson and Suchman are far superior in their ability to explain than are the more traditional analyses of relationships between demographic factors and the utilization of services. This superiority lies in the proposed linking mechanisms between personal characteristics and behavior. These studies also demonstrate that health decision making is a process in which the individual moves through a series of stages or phases. Interactions with persons or events at each of these stages influence the individual’s decisions and subsequent behavior.
Yet, even these sophisticated studies limit their focus to illness behavior; that is, to behavior undertaken in response to symptoms. The findings are, thus, of unknown relevance to the situation confronting the person who must decide whether to seek preventive or detection services before the appearance of events that he interprets as symptoms. Suchman explicitly notes the failure of his concepts of social structure and health orientation to account for preventive health actions.17 Stimulating the development of a preventive orientation in the public is the heart of most educational programs in public health.
A Model to Explain Health Behavior
Within the past decade several theoretical papers and empirical research reports have appeared which deal with a particular model for explaining health behavior in individuals who believe themselves to be free of symptoms or illness.18–26 A comprehensive description and critique of the model28 will be provided, as well as a presentation of research evidence that tends both to support it and to contradict it. An analysis will be made of the questions that remain unanswered and of the kinds of research that will be needed to answer these questions. The model does not attempt to provide a comprehensive explanation of all health action. Rather, what is attempted is the specification of several variables that appear to contribute significantly to an understanding of behavior in the health area.
Considerable detail will be provided although the model is far from having been proven valid and useful. This is justified on the grounds that the model seems to provide a most promising framework for explaining large segments of behavior relevant to health and for unifying what, at the moment, are unrelated findings from several investigations. Possibly, though the attempt will not be made in this paper, the model, formulated essentially to explain health behavior (in the sense used by Kasl and Cobb1) can ultimately be applied as well to explaining illness behavior and sick-role behavior.
Before turning to a presentation of the model itself, a few words about some of its general characteristics are in order. The major variables in the model are drawn and adapted from general social-psychological theory, notably the work of Lewin.27 The variables deal with the subjective world of the behaving individual and not with the objective world of the physician or the physicist. The two, no doubt, are correlated, but the correlation is far from perfect. The focus in the application of the model is to link current subjective states of the individual with current health behavior.
A truism in social psychology is that motivation is required for perception and action. Thus, people who are unconcerned with a particular aspect of their health are not likely to perceive any material that bears on that aspect of their health. Even if, through accidental circumstances, they do perceive such material, they will fail to learn, accept or use the information.
Not only is such concern or motivation a necessary condition for action; motives also determine the particular ways in which the environment will be perceived. That a motivated person perceives selectively in accordance with his motives has been verified in many laboratory studies29 as well as in field settings.30
The proposed model to explain health behavior grows out of such evidence. Specifically, it includes two classes of variables: 1. the psychological state of readiness to take specific action and, 2. the extent to which a particular course of action is believed, on the whole, to be beneficial in reducing the threat. Two principal dimensions define whether a state of readiness to act exists. They include the degree to which an individual feels vulnerable or susceptible to a particular health condition and the extent to which he feels that contracting that condition would have serious consequences in his case.
Readiness to act is defined in terms of the individual’s points of view about susceptibility and seriousness rather than the professional’s view of reality. But the model does not require that individuals be continuously or consciously aware of the relevant beliefs.
Evidence from studies to be discussed subsequently suggests that the beliefs that define readiness have both cognitive (i.e., intellectual) elements and emotional elements. The author’s opinion is that the underlying emotional aspects have greater value in accounting for behavior than do the cognitive elements.
Perceived Susceptibility
Individuals vary widely in the acceptance of personal susceptibility to a condition. At one extreme is the individual who, during interview, may deny any possibility of his contracting a given condition. In a more moderate position is the person who may admit to the “statistical” possibility of its occurrence but to whom this possibility has little reality and who does not really believe it will happen to him. Finally, a person may express a feeling that he is in real danger of contracting the condition. In short, as it has been measured, susceptibility refers to the subjective risks of contracting a condition.
Perceived Seriousness
Convictions concerning the seriousness of a given health problem may also vary from person to person. The degree of seriousness may be judged both by the degree of emotional arousal created by the thought of a disease as well as by the kinds of difficulties the individual believes a given health condition will create for him.31
A person may, of course, see a health problem in terms of its medical or clinical consequence. He would thus be concerned with such questions as whether a disease could lead to his death, or reduce his physical or mental functioning for long periods of time, or disable him permanently. However, the perceived seriousness of a condition may, for a given individual, include such broader and more complex implications as the effects of the disease on his job, on his family life and on his social relations. Thus a person may not believe that tuberculosis is medically serious, but may nevertheless believe that its occurrence would be serious if it created important psychological and economic tensions within his family.
Perceived Benefits of Taking Action and Barriers to Taking Action
The acceptance of one’s susceptibility to a disease that is also believed to be serious provides a force leading to action, but it does not define the particular course of action that is likely to be taken.
The direction that the action will take is influenced by beliefs regarding the relative effectiveness of known available alternatives in reducing the disease threat to which the individual feels subjected. His behavior will thus depend on how beneficial he thinks the various alternatives would be in his case. Of course, he must have available to him at least one action that is subjectively possible. An alternative is likely to be seen as beneficial if it relates subjectively to the reduction of one’s susceptibility to or seriousness of an illness. Again, the person’s belief about the availability and effectiveness of various courses of action, and not the objective facts about the effectiveness of action, determines what course he will take. In turn, his beliefs in this area are doubtless influenced by the norms and pressures of his social groups.
An individual may believe that a given action will be effective in reducing the threat of disease, but at the same time see that action itself as being inconvenient, expensive, unpleasant, painful or upsetting. These negative aspects of health action arouse conflicting motives of avoidance. Several resolutions of the conflict are possible. If the readiness to act is high and the negative aspects are seen as relatively weak, the action in question is likely to be taken. If, on the other hand, the readiness to act is low while the potential negative aspects are seen as strong, they function as barriers to prevent action.
Where the readiness to act is great and the barriers to action are also great, the conflict is more difficult to resolve. The individual is highly oriented toward acting to reduce the likelihood or impact of the perceived health danger. He is equally highly motivated to avoid action since he sees it as highly unpleasant or even painful.
Sometimes, alternative actions of nearly equal efficacy may be available. For example, the person who feels threatened by tuberculosis but fears the potential hazards of x-rays may choose to obtain a tuberculin test for initial screening.
But what can he do if the situation does not provide such alternative means to resolve his conflicts? Experimental evidence obtained outside the health area suggests that one of two reactions occur. First, the person may attempt to remove himself psychologically from the conflict situation by engaging in activities which do not really reduce the threat. Vacillating (without decision) between choices may be an example. Consider the individual who feels threatened by lung cancer who believes quitting cigarette smoking will reduce the risk but for whom smoking serves important needs. He may constantly commit himself to give up smoking soon and thereby relieve, if only momentarily, the pressure imposed by the discrepancy between the barriers and the perceived benefits.
A second possible reaction is a marked increase in fear or anxiety.32 If the anxiety or fear become strong enough, the individual may be rendered incapable of thinking objectively and behaving rationally about the problem. Even if he is subsequently offered a more effective means of handling the situation, he may not accept it simply because he can no longer think constructively about the matter.
Cues to Action
The variables which constitute readiness to act, that is, perceived susceptibility and severity as well as the variables that define perceived benefits and barriers to taking action, have all been subjected to research which will be reviewed in subsequent sections. However, one additional variable is believed to be necessary to complete the model but it has not been subjected to careful study.
A factor that serves as a cue or a trigger to trip off appropriate action appears to be necessary. The level of readiness (susceptibility and severity) provides the energy or force to act and the perception of benefits (less barriers) provides a preferred path of action. However, the combination of these could reach quite considerable levels of intensity without resulting in overt action unless some instigating event occurred to set the process in motion. In the health area, such events or cues may be internal (e.g., perception of bodily states) or external (e.g., interpersonal interactions, the impact of media of communication, knowledge that some one else has become affected or receiving a postcard from the dentist).
The required intensity of a cue that is sufficient to trigger behavior presumably varies with differences in the level of readiness. With relatively low psychological readiness (i.e., little acceptance of susceptibility to or severity of a disease) rather intense stimuli will be needed to trigger a response. On the other hand, with relatively high levels of readiness even slight stimuli may be adequate. For example, other things being equal, the person who barely accepts his susceptibility to tuberculosis will be unlikely to check upon his health until he experiences rather intense symptoms (e.g., spitting blood). On the other hand, the person who readily accepts his constant susceptibility to the disease may be spurred into action by the mere sight of a mobile x-ray unit or a relevant poster.
Unfortunately, the settings for most of the research on the model have precluded obtaining an adequate measure of the role of cues. Since the kinds of cues that have been hypothesized may be quite fleeting and of little intrinsic significance (e.g., a casual view of a poster urging chest x-ray), they may easily be forgotten with the passage of time. An interview taken months or years later could not adequately identify the cues. Freidson has described the difficulties in attempting to assess interpersonal influences as cues.33 Furthermore, respondents who have taken a recommended action in the past will probably be more likely to remember preceding events as relevant than will respondents who were exposed to the same events but never took the action. These problems make testing the role of cues most difficult in any retrospective setting. A prospective design, perhaps a panel study, will probably be required to assess properly how various stimuli serve as cues to trigger action in an individual who is psychologically ready to act.
Summary and Conclusions
Only a beginning has been made toward a systematic explanation of health and illness behavior. Many studies of the utilization of preventive and treatment services, while valuable for formulating public policy, do not throw light on the determinants of behavior. On the other hand, recent sociological research is demonstrating that health decision making is best thought of as a process in which the individual moves through each of a series of stages or phases. Events occurring at any of these stages influence choices at subsequent stages. Even such research is currently limited to explaining circumscribed aspects of health behavior.
A specific model to account for personal health decisions that are made in the absence of clear-cut symptoms shows promise of providing a means of explaining preventive health behavior. The model hypothesizes that a decision to obtain a preventive or detection test in the absence of symptoms will not be made unless the following conditions are satisfied:
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The individual is psychologically ready to take action relative to a particular health condition. The extent of readiness to act is defined by whether the individual feels susceptible to the condition in question and the extent to which its possible occurrence is viewed as having serious personal consequences.
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The individual believes that the preventive or test in question is both feasible and appropriate for him to use, would reduce either his perceived susceptibility to or the perceived severity of the health condition and no serious psychological barriers to the proposed action are present.
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A cue or stimulus occurs to trigger the response.
The strengths of the model are that it has appeared adequate to account for major variations in behavior in groups of individuals studied in a variety of settings, is composed of a small number of elements, and appears to be capable of application to a wide variety of health actions and beliefs. The dimensions included in the model are, at least in principle, capable of change through education.
Some defects have appeared in the model to date. Experimental manipulation of the variables has not been undertaken to any marked extent, data are lacking on the role of cues in explaining health behavior, many of the studies which lend support to the model were based on small and possibly non-representative samples, a number of supporting studies were necessarily done retrospectively although the model implies a prospective design, operational definitions of the model’s concepts have not been uniform, the variables have not yet been quantified beyond the nominal scale and the stability of the beliefs and reliability of the measures are not known.
In short, considerable research is still needed to demonstrate the model’s true explanatory value. However, evidence to date justifies continued support of such research.
Since health decisions are determined by a variety of personal, interpersonal and situational factors, attempts to induce people to change their health actions may successfully be undertaken at various points in the decision process. Efforts to minimize barriers to action, to maximize convenience and to provide intensive cues to action are believed to increase public acceptance of health programs. However, after all such attempts have been made, a group will remain which is not psychologically ready to act and which will, therefore, not respond to cues to seek health services. For that group persuasive efforts will need to be focused directly on their beliefs or their behavior.
The beliefs identified in the model (as well as the use of associated preventive health measures) are not distributed equally in the population. The beliefs and the behavior tend more to be exhibited by upper socioeconomic groups than by lower. Educational programs designed to increase the acceptance of the beliefs as well as the adoption of preventive health behavior should be directed primarily to the poorly educated, to those of lower income and to non-white groups. However, the very groups to be reached tend, through a process of self-selection, not to expose themselves to scientific and health information transmitted through the mass media. Also, the mass media have not been notably effective in changing existing beliefs and behavior, although sufficient research has not been done in health contexts. More emphasis should be placed on methods that employ personal influence in face-to-face contacts, an approach which is widely held to be effective in educating members of the affected groups, though very little relevant research evidence can be cited. Some new approaches described might be used in enhancing the effects of group discussion techniques. Moreover, research and demonstration are needed to determine the extent to which school health programs can exert a significant and lasting effect on the acquisition of health beliefs and behavior.
The critical review presented in this paper suggests a need for research on the following unsolved problems.
With respect to the explanatory model, more evidence, especially experimental evidence, is needed on the validity and relative contributions of each of the model variables to personal health decision making, including data on the importance of cues. Operational definitions of each of the model variables are needed which are related to the concepts covered, which correlate with criterion measures of behavior, which can be measured reliably, and which are quantified on at least an ordinal scale.
With respect to the problem of inducing behavioral change, research on mass communication and personal influence methods needs to be extended to determine the principles by which individuals, especially those in lower socioeconomic groups can be persuaded to alter their health opinions, attitudes and behavior. More extensive research in health settings is needed to resolve inconsistencies which can be experimentally induced between beliefs and behavior. Recent research suggests the desirability of more intensive study of the role of emotionally arousing factors in education and on the conditions which increase the effects of emotionally arousing messages upon attitude and behavior change.
